Shah Rukh Khan and Kajol were Karan Johar's first choices to play Rahul and Anjali, respectively. They had promised to be a part of Johar's first film back when he was the assistant director on DDLJ.
Rani Mukerji was only 19 during the shoot.
Karan originally planned to cast Twinkle Khanna as the second lead and had even named the character Tina after Twinkle’s nickname, but was forced to cast Rani after the former turned the role down.
In fact, Aditya Chopra and Shah Rukh suggested Rani Mukerji for the role after watching her in Raja Ki Aayegi Baaraat.
Remember the iconic moment when Kajol’s sari flies away dramatically in the song, ‘Ladki Badi’? It was initially a joke between Farah Khan and and Karan during the shoot but was later kept in the film
Designer Manish Malhotra, Farah Khan, choreographer Geeta Kapoor, director Nikhil Advani, and even Karan Johar's mom, Hiroo Johar, have appeared in different cameos in the film and went unnoticed.
Aman's role was first offered to Saif Ali Khan but he rejected it. And later, Salman Khan straight-forwardly asked Karan for the role when he met him at a bash thrown by Chunky Pandey.
Remember the cute little Sardar boy, Parzaan Dastur, in the film? When SRK's son Aryan visited the film's sets, he dressed him up just like him.
Karan Johar wanted Rani's talkie portions to be dubbed due to her husky voice, not knowing that her voice would become her trademark.
Jugal Hansraj created the tune for 'Tum Paas Aaye' in the shower and gave it to Karan Johar.
The girl who played little Anjali, Sana Saeed, refused to use glycerine for the scenes that required crying. So, Johar would be particularly mean to her and make her cry.
Shah Rukh and Kajol used trampolines to jump for the basketball scenes.
When he first watched the film, Shah Rukh didn't enjoy the ending because it had too much crying in it.
Shah Rukh's iconic Polo Sport t-shirt from 'Koi Mil Gaya' cost £75, and Johar and designer Manish Malhotra debated buying it for three hours before eventually picking it up.
Sushmita Sen told Shah Rukh that she wanted to take acting seriously after she watched the film.
During the bicycle sequence in 'Yeh Ladki Hai Deewana', Kajol lost control of her bike, fell flat on her face, and was knocked unconscious, while also injuring her knee.
The fall was bad enough for Kajol to temporarily lose her memory. The only person she could remember was her then-boyfriend and now-husband Ajay Devgn.
It was Kajol's idea to include Tina's death scene in the film.
Parzaan Dastur, who played the little Sardar boy on screen, didn't even dub his only line in the movie — 'Tussi jaa rahe hai? Tussi na jaao'. It was dubbed by another child artist, Kaivalya Chheda.
Johar initially had a problem with the line 'Main toh hil gaya' in the song 'Koi Mil Gaya' because he thought it sounded 'downmarket,' but he later agreed to it.
A scene in the film has Hiroo Johar, Karan's mum walk by whereas another has designer Manish Malhotra and choreographer Farah Khan, both best friends of Karan Johar, as college students.
The art director, Sharmishta Roy, was told to take inspiration for the college sets from TV show Beverly Hills, 90210 and Archie comics.
Karan Johar apparently was in tears while shooting Rahul and Anjali's reunion scene at the camp.
Kajol actually cried through the climax where Rahul and Anjali finally get together by watching close-ups of SRK crying in the scene.
Even though his clothes became all the rage after the movie's release, Shah Rukh admitted he was embarrassed to wear his costumes in the movie as he felt they were too tight.
Salman Khan and Kajol were not on talking terms while shooting 'Saajanji Ghar Aaye'.
Kajol really didn't want to shoot this adorable laugh from 'Ladki Badi Anjani Hai' because she thought it was too dramatic.
The hook for 'Saajanji Ghar Aaye' was suggested by Pamela Chopra, Yash Chopra's wife. It is from a popular Punjabi wedding song, 'Hum Ghar Saajan Aaye'.
The second stanza from 'Tujhe Yaad Na Meri Aayee' with the lines 'Teri kar di god bharai' never made the final cut. But it was initially used in a baby shower scene for Rani Mukerji in the film.
. As iconic as it eventually became, Johar admitted that he thought the film was 'unusually silly'.
And both Johar and Shah Rukh agree that Rahul was a selfish prick.
It is the only bollywood movie, which has won all the awards for major acting categories.
Rani Mukerji and Kajol are cousins in real life.
When Karan Johar wanted to make a film, he had 2 story ideas for 2 films and he dint know which film to make. Then he decided to mix the two stories and make it into one film and KKHH happened.
Aamir Khan turned down the role of Aman Mehra because he didn't want to be overshadowed by Shah Rukh Khan.
Ajay Devgan was also offered the role Aman Mehra but he also declined it.
This was the first of five successive movies made by Karan Johar to have the movie title start with K.
The film Movie was shot at Tamil Nadu's Nilgiri Hills, Ooty.
Chandrachur Singh was also offered the role of Aman Mehra.
A cover version of 'Raghupati Raja Ram' was in the International album DJ Yano - Afro Project Volume 4.
In the scene where the camp was around the fire and playing the film charades game, the film made references to the movies Hum Aapke Hain Koun and Rangeela.
Famous choreographer Geeta Kapoor appeared in the song 'Tujhe Yaad Na Meri Aai'.
Manisha Koirala also turned down Tina's role, later played by Rani Muhkerji.
The theatres in America and Canada were very happy with how much business Kuch Kuch Hota Hain was doing since its release on October 16,1998. The theatre owners did not want to show any other film.
It was on the sets of Mahesh Bhatt's Chaahat (1996) that Karan Johar narrated the script of his debut Bollywood venture, this film, to Shah Rukh Khan.
The scene where Shah Rukh Khan forgets to wear his pants was recreated from Dil to Pagal Hai (1997).Co-incidentally, The act was originally shot on Shah Rukh Khan itself.
Salman Khan was seen with a close crop buzz haircut because he was shooting for the movie Dus
The song Koi Mil Gaya was sampled from Andrew Lloyd Webbers song Take That Look Of Your Face.
The film won the National Film Award for Best Popular Film Providing Wholesome Entertainment
Outside India, the film was the highest grossing Hindi film ever until its record was broken by Karan's next directorial, Kabhi Khushi Kabhie Gham (2001).
